Polymers including at least one reactive silicon group in the molecule have been known to be characterized by availability of rubbery cured products by crosslinking via formation of a siloxane bond, which is accompanied by a hydrolysis reaction or the like of the reactive silicon group due to the moisture and the like even at room temperatures.
Among these polymers having a reactive silicon group, organic polymers such as polyoxyalkylene based polymers and polyisobutylene based polymers including a typical main chain skeleton are disclosed in Patent Document 1, Patent Document 2 etc., and have been already produced industrially and used broadly in applications such as sealants, adhesives, and paints. Furthermore, a large number of reports including Patent Document 3 have been made also regarding curable compositions constituted with a polymer having a main chain skeleton of polysiloxane, particularly diorganopolysiloxane.
When such polymers are used in curable compositions for use in sealants, adhesives, paints and the like, a variety of characteristics such as curability and adhesiveness, as well as mechanical characteristics of the cured products, and the like are required.
The curable composition including the polymer having a reactive silicon group is cured using a curing catalyst such as an organic tin compound which is commonly typified by dibutyltin bis(acetylacetonato) and which has a carbon-tin bond. In use, when curing within a short period of time is required, generally employed method includes increasing the amount of the curing catalyst, and the like. However, in recent years, toxicity of the organic tin compounds has been indicated, and thus these compounds must be carefully used in light of environmental security. As the curing catalyst other than the organic tin compounds, tin carboxylates and other metal carboxylates are disclosed in Patent Document 4 and Patent Document 5, and catalyst systems in which carboxylic acid and an amine compound are used in combination are disclosed in Patent Document 6. However, many of these catalysts are inferior in curability as compared with organic tin catalysts.    Patent Document 1: JP-A-52-73998    Patent Document 2: JP-A-63-6041    Patent Document 3: JP-A-55-43119    Patent Document 4: JP-A-55-9669    Patent Document 5: JP-A-2003-206410
Patent Document 6: JP-A-5-117519